will remove organic chemicals and stuff, but only for a few short weeks. Then it just becomes surface area for bacteria. So you might as well just provide surface area media to start with. Anything convoluted or porous will do. Eheim, fluval, and seachem all sell the stuff. I run the fluval ceramic coarse mechanical rings, then some filter floss, then two baskets of biomedia, a mixture of the fluval ceramic media and the seachem media. The media can be taken out to jump start new tanks anytime you want.